The present invention relates to a system for producing pressure sensitive stamps, and more particularly to a method which allows for the production of a coil of such pressure sensitive stamps without a backing or liner on the entire coil.
It has long been known to roll a strip of stamps into a coil to save space and to provide a convenient mechanism for detaching one or more stamps from a plurality of others. However, such a coil configuration had been limited to traditionally known stamps which required moistening on a glue side before being adhered to an envelope.
More recently, so-called xe2x80x9cself adhesivexe2x80x9d stamps have been becoming more and more popular. These stamps do not have to be moistened, but rather are provided with a pressure sensitive adhesive layer which is adhered to the envelope. The pressure sensitive adhesive layer is typically covered with a protective backing, or liner, consisting of a strip of non-adhesive material, generally of the same width of or wider than the strip of stamps, which is peeled away before the stamp is adhered to the envelope in order to expose the adhesive layer.
It has been proposed to roll such self-adhesive stamps into a coil in order to enjoy the convenience and space-saving characteristics associated therewith. However, when using known pressure sensitive adhesive stamp designs, rolling them into a coil requires that the entire coil of stamps have a strip of protective liner backing the adhesive layer. This liner is required in order to prevent the adhesive layer from adhering to the printed, unprotected face of the stamp material which is wound immediately beneath the liner which provides a protective barrier. Providing a strip of liner for the entire coil of stamps, however, is undesirable for several reasons. One such reason relates to environmental concerns. The liner strip comprises unnecessary waste, which adversely impacts the environment. Moreover, the liner increases the material costs associated with manufacturing the stamps. Furthermore, when a liner is used, one is required to unroll a stamp off the coil, remove the stamp from the liner, and detach it from the next following stamp before adhering the stamp to the envelope. It would be easier for the user if the stamp could simply be unrolled, detached from the following stamp, and adhered to the envelope without having to remove a liner.
In order to remedy the above concerns, and referring to FIG. 1, a coil 10 of stamps has been developed. Coil 10 comprises a continuous strip 12 of stamps rolled on itself, similar to a roll of tape. It should be noted that the strip 12 of stamps does not include a liner, or backing layer, protecting the pressure sensitive adhesive over its entire length. A piece of liner material 14 may be provided, however, at the center (i.e., the end) of coil 10 in order to inhibit lint, dirt, dust and the like from adhering to the stamps at the center of the coil, thereby preventing a sure adhesion of those stamps to the envelope at the time of use, and in order to meet security requirements imposed by the United States Postal Service or any other issuer of the stamps. A piece of liner material 16 may also be provided at the outer portion (i.e., the beginning) of coil 10 in order to facilitate removal of the first stamp or first few stamps from the strip 12 of stamps. However, it should be noted that as the strip 12 of stamps may be several yards, or more, in length the sections of the strip 12 which include a liner layer are relatively very small.
While the coil 10 of stamps shown in FIG. 1 is desirable in that it does not include a liner over the entire strip of stamps comprising the coil, the production of coil 10 introduces new problems of its own. More specifically, known methods for manufacturing stamps, even coils of stamps, cannot be used to create a coil of stamps which does not include a liner over the entire strip of stamps. The specific problems encountered using known methods for the production of coils of stamps which include a liner over the entire strip of stamps, and the novel solutions to those problems which comprise the present invention, are discussed in detail below.
What is desired, therefore, is a system and method of creating a coil of stamps, which coil does not require a liner layer over the entire strip of stamps comprising the coil, and which avoids the problems associated with known methods for the production of coils of stamps which include a liner over the entire strip of stamps.
Accordingly, it is an object of the present invention to provide a system and method of creating a coil of stamps.
A more specific object of the present invention is to provide a system and method of creating a coil of stamps, which coil does not require a liner layer over the entire strip of stamps comprising the coil.
A further object of the present invention is to provide a system and method having the above characteristics and which avoids the problems associated with known methods for the production of coils of stamps which include a liner over the entire strip of stamps.
These and other objects of the present invention are achieved by provision of a system for creating a coil of stamps from a web of stamp material having an adhesive applied to a side thereof. The system includes a substantially cylindrical anvil and a perforation die cooperating therewith with the web of stamp material passing therebetween in order to perforate the web of stamp material. The web of stamp material is passed between the anvil and the perforation die with the side of the web of stamp material having the adhesive applied thereto facing the anvil. The anvil is chilled so as to inhibit the adhesive applied to the web of stamp material from adhering thereto as the web of stamp material is perforated by cooperation of the perforation die and the anvil.
The anvil may be chilled from an outer surface thereof, or may be hollow and chilled from an inner surface thereof. In the former case, the system preferably includes a trough holding a chilling material through which at least a portion of an outer surface of the anvil is passed in order to chill the outer surface thereof. Most preferably, the chilling material comprises dry ice. Where the anvil is chilled from an inner surface thereof, a cooling fluid is preferably passed therethrough.
The system preferably also includes a liner application mechanism for applying a liner material to no more than a portion of the web of stamp material. Most preferably, the liner application mechanism includes a spool of liner material and a cutting mechanism for cuffing the liner material into a plurality of discrete pieces of liner material having a predetermined length before the liner material is applied to the side of the web of stamp material having the adhesive applied thereto. Preferably, each of the plurality of discrete pieces of liner material includes at least one perforation, and the at least one perforation is aligned with a perforation in the web of stamp material. It is also preferable that the liner application mechanism be located after the anvil and the perforation die.
In addition, the system preferably also includes a coiling mechanism for creating discrete coils of stamps from the web of stamp material. Most preferably, the coiling mechanism includes at least one roller around which the web of stamp material is wound in order to place the web of stamp material in tension and a bursting blade extending across a width of the web of stamp material. The bursting blade includes a narrow tip and is movable substantially perpendicular to the web of stamp material such that when moved fully toward the web of stamp material, the bursting blade breaks a plane formed by the web of stamp material. The bursting blade is moved forcefully toward the web of stamp material adjacent to a perforation in the web of stamp material in order to burst the perforation and separate a coil of stamps from the remainder of the web of stamp material. Most preferably, the narrow tip of the bursting blade has a shape selected from a group consisting of sharp, rounded, serrated, or straight shapes or combinations of these.
The invention and its particular features and advantages will become more apparent from the following detailed description considered with reference to the accompanying drawings.